Alert archive / South Dakota / Severe Thunderstorm Warnings in 2026

Severe Thunderstorm Warning 73, NWS Sioux Falls, SD

May 24, 2026Lyon County, Iowa; Rock County, Minnesota; Lincoln County, Minnehaha County, South Dakota

NWS Sioux Falls, SD issued this severe thunderstorm warning at May 24, 2026, 11:29 PM CDT for Lyon County, Iowa; Rock County, Minnesota; Lincoln County, Minnehaha County, South Dakota. It was in force for 46 min. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
May 24, 2026, 11:29 PM CDT (04:29 UTC)
Expired
May 25, 2026, 12:15 AM CDT
In force
46 min
Issued by
NWS Sioux Falls, SD
Area
Storm-based polygon
Hail
1.25 in
Wind
60.0 mph

Counties Lyon County, IA, Rock County, MN, Lincoln County, SD, Minnehaha County, SD

The radar

The Sioux Falls radar (KFSD), 8 km from the middle of the area, began a volume at 04:30 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

TimeReportWhereRemark
May 24, 11:30 PM CDTHAIL 12 Sw Sioux Falls, SDGot an mping report of Quarter sized hail in Sioux Falls. Time estimated via radar.
May 24, 11:40 PM CDTHAIL 12 W Brandon, SDmPING Report of Quarter (1.00 in.) sized hail just west of Brandon. Time estimated via radar.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched 2 storm reports to this severe thunderstorm warning; the first came 1 minutes after it went out.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Aberdeen, SD (KABR), launched 00:00Z, 4.5 hours before the alert went out and 205 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Aberdeen, SD at 00:00Z on 2026-05-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 29 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Aberdeen, SD at 00:00Z on 2026-05-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 48 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
29 J/kg
Mixed-layer CIN
-28 J/kg
Mixed-layer LCL
3042 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
48 m²/s²
0-3 km storm-relative helicity
115 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted.

628 
WUUS53 KFSD 250429
SVRFSD
IAC119-MNC133-SDC083-099-250515-
/O.NEW.KFSD.SV.W.0073.260525T0429Z-260525T0515Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Sioux Falls SD
1129 PM CDT Sun May 24 2026

The National Weather Service in Sioux Falls has issued a

* Severe Thunderstorm Warning for...
  Northwestern Lyon County in northwestern Iowa...
  Southwestern Rock County in southwestern Minnesota...
  Southeastern Minnehaha County in southeastern South Dakota...
  Northwestern Lincoln County in southeastern South Dakota...

* Until 1215 AM CDT.

* At 1129 PM CDT, a severe thunderstorm was located over Sioux Falls,
  moving east at 30 mph.

  HAZARD...60 mph wind gusts and half dollar size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees.

* This severe thunderstorm will be near...
  Sioux Falls, Brandon, Harrisburg, Lake Alvin State Recreation 
  Area, Corson, and Rowena around 1135 PM CDT.
  Valley Springs around 1140 PM CDT.
  Larchwood around 1145 PM CDT.

Other locations in the path of this severe thunderstorm include Hills
and Beaver Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

To report severe weather, contact your nearest law enforcement
agency. They will send your report to the National Weather Service
office in Sioux Falls.

&&

LAT...LON 4346 9693 4363 9692 4364 9633 4340 9638
TIME...MOT...LOC 0429Z 270DEG 27KT 4354 9674 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.25 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Samet
3 follow-up statements
025 
WWUS53 KFSD 250443
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
1143 PM CDT Sun May 24 2026

IAC119-MNC133-SDC083-099-250515-
/O.CON.KFSD.SV.W.0073.000000T0000Z-260525T0515Z/
Lyon IA-Rock MN-Minnehaha SD-Lincoln SD-
1143 PM CDT Sun May 24 2026

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1215 AM CDT
FOR NORTHWESTERN LYON...SOUTHWESTERN ROCK...SOUTHEASTERN MINNEHAHA
AND NORTH CENTRAL LINCOLN COUNTIES...

At 1142 PM CDT, a severe thunderstorm was located near Rowena, or
near Sioux Falls, moving east at 30 mph.

HAZARD...60 mph wind gusts and half dollar size hail.

SOURCE...Public. At 1130 PM, quarter sized hail was reported 
         in Sioux Falls, SD.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
  Brandon, Larchwood, Valley Springs, Corson, Rowena, Hills and 
  Beaver Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
Sioux Falls.

&&

LAT...LON 4346 9689 4363 9673 4364 9633 4340 9638
TIME...MOT...LOC 0442Z 271DEG 26KT 4352 9664 

HAIL THREAT...OBSERVED
MAX HAIL SIZE...1.25 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Samet
221 
WWUS53 KFSD 250459
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
1159 PM CDT Sun May 24 2026

IAC119-MNC133-SDC083-099-250515-
/O.CON.KFSD.SV.W.0073.000000T0000Z-260525T0515Z/
Lyon IA-Rock MN-Minnehaha SD-Lincoln SD-
1159 PM CDT Sun May 24 2026

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1215 AM CDT
FOR NORTHWESTERN LYON...SOUTHWESTERN ROCK...SOUTHEASTERN MINNEHAHA
AND NORTH CENTRAL LINCOLN COUNTIES...

At 1159 PM CDT, a severe thunderstorm was located near Rowena, or 11
miles east of Sioux Falls, moving east at 30 mph.

HAZARD...60 mph wind gusts and half dollar size hail.

SOURCE...Public. At 1130 PM, quarter sized hail was reported in 
         Sioux Falls, SD.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
Sioux Falls, Brandon, Harrisburg, Larchwood, Valley Springs, Hills,
Beaver Creek, Lake Alvin State Recreation Area, Corson, and Rowena.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
Sioux Falls.

&&

LAT...LON 4346 9679 4353 9660 4363 9657 4364 9633
      4340 9638 4345 9680
TIME...MOT...LOC 0459Z 273DEG 25KT 4349 9651 

HAIL THREAT...OBSERVED
MAX HAIL SIZE...1.25 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Samet
639 
WWUS53 KFSD 250512
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
1212 AM CDT Mon May 25 2026

IAC119-MNC133-SDC083-099-250522-
/O.EXP.KFSD.SV.W.0073.000000T0000Z-260525T0515Z/
Lyon IA-Rock MN-Minnehaha SD-Lincoln SD-
1212 AM CDT Mon May 25 2026

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN LYON...
SOUTHWESTERN ROCK...SOUTHEASTERN MINNEHAHA AND NORTH CENTRAL LINCOLN
COUNTIES WILL EXPIRE AT 1215 AM CDT...

The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However, small
hail and gusty winds are still possible with this thunderstorm.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Sioux Falls.

&&

LAT...LON 4346 9679 4353 9660 4363 9657 4364 9633
      4340 9638 4345 9680
TIME...MOT...LOC 0512Z 270DEG 27KT 4349 9638 

$$

Samet

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Sioux Falls, SD wrote its last area forecast discussion before this severe thunderstorm warning went out at May 24, 10:50 PM CDT, 39 minutes earlier. Its key messages:

  • Isolated to scattered thunderstorms possible during the late afternoon through early overnight hours (5pm-11pm) east of Highway 281. Primary risks of 2 inch hail and 65 mph winds.
  • Isolated to scattered thunderstorms may redevelop Monday evening into Monday night over NW Iowa and NE Nebraska. Non- zero severe weather risks may bring gusty winds and hail.
  • Temperatures remain 10+ degrees above normal into mid-week, but expect a slight cooldown back to normals by next weekend.
  • Rain risks return Friday into next weekend (20-40%), however severe weather chances are very low.
Area forecast discussion, May 24, 10:50 PM CDT, 39 minutes before
Area Forecast Discussion
National Weather Service Sioux Falls SD
1050 PM CDT Sun May 24 2026

.KEY MESSAGES...

- Isolated to scattered thunderstorms possible during the late
  afternoon through early overnight hours (5pm-11pm) east of
  Highway 281. Primary risks of 2 inch hail and 65 mph winds.

- Isolated to scattered thunderstorms may redevelop Monday
  evening into Monday night over NW Iowa and NE Nebraska. Non-
  zero severe weather risks may bring gusty winds and hail.

- Temperatures remain 10+ degrees above normal into mid-week,
  but expect a slight cooldown back to normals by next weekend.

- Rain risks return Friday into next weekend (20-40%), however
  severe weather chances are very low.

&&

.UPDATE...
Issued at 1049 PM CDT Sun May 24 2026

With ongoing severe weather across parts of the area, the next
update will out before 5 am on May 25th.

&&

.DISCUSSION...
Issued at 1211 PM CDT Sun May 24 2026

THIS AFTERNOON/EVENING: Temperatures continue to rise towards and
into the 80s this afternoon. Initial mid-lvl vorticity tracking
across South Dakota this morning will keep a narrow channel AC
focused along the Ridge and Minnesota River valley early this
afternoon. Increasing southwesterly surface flow will continue
to pull modest boundary layer moisture northward, but some of
the high-res CAMs are overdoing current moisture at mid-day.
Nevertheless, we should eventually see more consistent
mid/upr-50 dew points arrive by late afternoon. The arrival of
slightly enhanced mid-lvl lapse rates will push MLCAPE values
towards the 1500-2200 J/KG layer by late afternoon. The main
question will then become "where does initiation occur?". Some
preference today for a weak area of surface convergence and low-
lvl jet convergence towards the Highway 14 corridor and into
the Minnesota River valley after 4pm. With inhibition weakened
further south towards the MO River, additional
isolated/scattered development could take place by early evening
further west along a weak dry line near the James River valley,
but this development is much less certain and more conditional
based on weaker convergence. It's the arrival of mid-lvl
vorticity in the 00-03Z window that may help development further
develop and linger into the early overnight hours before low-
lvl flow veers and pushes convection eastward.

Regarding hazards, the increase in effective shear towards the
30-40 knot mark support a few supercells, with analogs
suggesting 1.5-2" hail potential. A few wind gusts to 60-70 mph
may be possible given steep low-lvl lapse rates, but only
modest DCAPE. The tornado risk remains very low. The west-east
slow storm movement through the Highway 14 corridor this evening
could lead lead to minor flash flood risks with HREF PMM data
suggesting 1-2" per hour rates. Storm risks lower quickly after
midnight with a quiet remaining overnight forecast.

MEMORIAL DAY: Even warmer temperatures are expected for Memorial day
as winds remain southwesterly. Highs are expected to rise into the
upper 80s to lower 90s. One thing to note will be a rise in
afternoon dewpoints towards the lower 60s that may push heat index
values into the 90s. Will also need to monitor the potential for
isolated convection to form Monday evening across portions of north
central/northwestern Iowa into northeastern Nebraska, given the
slightly dirty mid-lvl flow remaining in the Plains. Several CAMS
(more NAM based), all suggest low-end development by late afternoon
to early evening, potentially driven by weak low-lvl convergence on
the developing LLJ. Shear remains rather weak but instability and
mid-lvl lapse rates of more than sufficient. Could see a few
stronger storms with localized downburst winds and severe hail if
trigger mechanism can be determined.  This activity may quickly
weaken after sunset, but continue to drift north into the overnight
hours.

TUESDAY-THURSDAY: The middle of the week favors dry and mild
conditions as a mid-lvl ridge builds through the Plains and extends
northward into Central Canada.  Residing under the ridge of this
quasi-blocking pattern would suggest very weak flow aloft, a slight
influence from east southeasterly surface winds, and dry conditions
with afternoon CU.

FRIDAY-SUNDAY: A broad mid-lvl ridge over the CONUS remains in place
through next weekend.  However, we begin to see eastward shifts in
the the dominant surface high over the Great Lakes, allowing a
better channel of low-lvl moisture to move through the Mid/Upr MO
river valley. What develops is a nearly daily low (20-40%) risk for
shower and thunderstorms, mostly within the peak diurnal timeframe.
Shear and instability in this pattern will be quite weak, so non-
severe thunderstorms are favored.  Temperatures are also favored to
drop closer to seasonal average in the middle to upper 70s.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 634 PM CDT Sun May 24 2026

Showers and thunderstorms have developed across the area late this
afternoon. The storms currently extend along a line approximately
from KMML down through about KAGZ. Some of these storms are produce
large hail and strong winds. These storms will continue to track to
the east and look to make it through the KFSD terminal area. A
little uncertainty remains for KSUX as drier air my prevent storms
from making it KSUX but did include a PROB30 group anyway. Should
see thunderstorms chances wane towards midnight or so. After that,
quiet conditions and southerly winds will persist through the night.

Winds will turn southeasterly for the day tomorrow with gusts up to
20-25 knots. There could be additional storm that develop after the
TAF period ends.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
IA...None.
NE...None.

&&

UPDATE...05
DISCUSSION...Dux
AVIATION...Meyers
Hazardous weather outlook, May 24, 12:27 PM CDT, 11 hours 2 minutes before
Hazardous Weather Outlook
National Weather Service Sioux Falls SD
1227 PM CDT Sun May 24 2026

IAZ001>003-012>014-020>022-031-032-MNZ071-072-080-081-089-090-097-
098-NEZ013-014-SDZ039-040-054>056-060>062-065>071-251730-
Lyon-Osceola-Dickinson-Sioux-O'Brien-Clay-Plymouth-Cherokee-
Buena Vista-Woodbury-Ida-Lincoln-Murray-Cottonwood-Nobles-Jackson-
Pipestone-Rock-Dixon-Dakota-Kingsbury-Brookings-Miner-Lake-Moody-
Hanson-McCook-Minnehaha-Hutchinson-Turner-Bon Homme-Yankton-Union-
1227 PM CDT Sun May 24 2026

This Hazardous Weather Outlook is for northwest Iowa, west central
Iowa, southwest Minnesota, northeast Nebraska, east central South
Dakota and southeast South Dakota.

.DAY ONE...This afternoon and tonight.

Isolated to scattered strong to severe storms are possible after 5pm
this afternoon and may continue through 11pm. The primary threats
will be large hail up to 2 inch hail and 65 mph wind gusts.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Scattered thunderstorms may again be possible Monday evening and
overnight. While the risks for severe weather are low, a storm or two
could produce marginally severe hail around 1 inch and brief 50 mph
wind gusts.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed after 5pm and continuing through
11pm.

SDZ038-050-052-053-057>059-063-064-251730-
Beadle-Gregory-Jerauld-Sanborn-Brule-Aurora-Davison-Charles Mix-
Douglas-
1227 PM CDT Sun May 24 2026

This Hazardous Weather Outlook is for central South Dakota, east
central South Dakota, south central South Dakota and southeast
South Dakota.

.DAY ONE...This afternoon and tonight.

Hazardous weather is not expected at this time.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Additional showers and thunderstorms will be possible on Monday
mainly east of I-29.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

In the hours before

Local storm report, May 24, 7:50 PM CDT, 3 hours 39 minutes before
Preliminary Local Storm Report
National Weather Service Sioux Falls SD
750 PM CDT Sun May 24 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0747 PM     Hail             4 N Utica               43.03N 97.50W
05/24/2026  E1.00 Inch       Yankton            SD   Emergency Mngr

&&

MM
Local storm report, May 24, 8:07 PM CDT, 3 hours 22 minutes before
Preliminary Local Storm Report
National Weather Service Sioux Falls SD
807 PM CDT Sun May 24 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0801 PM     Hail             3 ESE Menno             43.22N 97.51W
05/24/2026  E1.50 Inch       Hutchinson         SD   Public

&&

MM
Local storm report, May 24, 8:33 PM CDT, 2 hours 56 minutes before
Preliminary Local Storm Report
National Weather Service Sioux Falls SD
833 PM CDT Sun May 24 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0810 PM     Hail             5 WSW Mayfield          43.05N 97.40W
05/24/2026  E1.50 Inch       Yankton            SD   Law Enforcement

&&

MM
Local storm report, May 24, 9:40 PM CDT, 1 hour 49 minutes before
Preliminary Local Storm Report
National Weather Service Sioux Falls SD
940 PM CDT Sun May 24 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0905 PM     Hail             Freeman                 43.35N 97.43W
05/24/2026  M1.50 Inch       Hutchinson         SD   Public

            Freeman Fire Rescue reported pea to
            Ping-Pong ball sized hail in Freeman. Time
            was estimated via radar.

&&

IG
Local storm report, May 24, 9:54 PM CDT, 1 hour 35 minutes before
Preliminary Local Storm Report
National Weather Service Sioux Falls SD
954 PM CDT Sun May 24 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0905 PM     Hail             Freeman                 43.35N 97.43W
05/24/2026  E2.00 Inch       Hutchinson         SD   Public

            Received a photo of 2 inch hail in Freeman
            via social media. Timing was estimated from
            radar.

&&

IG
Local storm report, May 24, 10:39 PM CDT, 50 minutes before
Preliminary Local Storm Report
National Weather Service Sioux Falls SD
1039 PM CDT Sun May 24 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0605 PM     Hail             Woodstock               44.01N 96.10W
05/24/2026  E1.25 Inch       Pipestone          MN   Trained Spotter

            A trained spotter reported half dollar sized
            hail in Woodstock, MN. Time estimated via
            radar.

&&

IG

The office that day

Everything else NWS Sioux Falls, SD issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 24, 10:42 PM CDTSevere Thunderstorm WarningFSDLyon48 min
May 25, 1:12 AM CDTSevere Thunderstorm WarningFSDLyon, O'Brien, Osceola, Sioux48 min
May 24, 7:14 PM CDTSevere Thunderstorm WarningFSDMurray, Nobles46 min
May 24, 7:39 PM CDTSevere Thunderstorm WarningFSDPipestone51 min
May 24, 7:13 PM CDTSevere Thunderstorm Warning Considerable damage threatFSDBon Homme, Yankton47 min
May 24, 7:57 PM CDTSevere Thunderstorm WarningFSDYankton48 min
May 24, 8:01 PM CDTSevere Thunderstorm WarningFSDHutchinson, Turner44 min
May 24, 8:37 PM CDTSevere Thunderstorm WarningFSDClay, Turner, Yankton38 min
May 24, 8:41 PM CDTSevere Thunderstorm WarningFSDHutchinson, Turner49 min
May 24, 9:24 PM CDTSevere Thunderstorm WarningFSDLincoln, Minnehaha, Turner51 min
May 24, 10:04 PM CDTSevere Thunderstorm WarningFSDMcCook41 min
May 24, 10:10 PM CDTSevere Thunderstorm WarningFSDLincoln, Minnehaha, Turner50 min
May 24, 10:36 PM CDTSevere Thunderstorm WarningFSDMcCook, Minnehaha39 min
May 24, 11:29 PM CDTFlash Flood WarningFSDMinnehaha72 min

Nearby

Severe Thunderstorm Warnings in South Dakota, 2026Severe Thunderstorm Warnings in Iowa, 2026Severe Thunderstorm Warnings in Minnesota, 2026Every severe thunderstorm warning in 2026

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.